[Python-Dev] multi-version parallel-installed modules

[Neal Becker]

Is there any proposal to accommodate having parallel-installed multiple 
versions of modules?

I have client code in multiple projects using version x.y of a C-compiled 
module A.

I want to test a new version x.z of module A, but all client software needs 
to be recompiled against the new version.  If I just install the module, all 
the other client software breaks.

I know I could test using virtualenv, but there would be a lot of modules to 
install into virtualenv to run the tests, so this would be cumbersome.  I'd 
prefer to have multiple version co-exist so I could update projects to the 
new version at my convenience.

How does this situation happen?  I have lots of c++ code using pyublas, 
which allows c++ code written to the boost::ublas interface to operate on 
numpy vectors/matrixes.  pyublas is built against boost libs. pyublas 
installs a module, whose purpose is to register conversions.

When I update boost libs, I have to rebuild pyublas and install the updated 
module.  Then rebuild my client software modules.  If pyublas is built 
against a different boost version than my client modules, the conversions 
will fail.